Of the many significant innovations of modern medical practice, one of the most enduring is the use of sutures to close and secure surgical and traumatic wounds and the like. Although suturing techniques have been refined through the years, the basic needle and thread sewing approach has remained until recent times.
In the past few years, surgical staples have been introduced to replace the use of sutures in many wound closure situations. Surgical stapls offer the potential of important improvements over the suture art. For example, many staples can be delivered and applied by one surgical stapling tool in quick succession, thus greatly hastening the closure of a wound. Also, surgical stapling tools apply the same amount of bending and crimping to each staple, so that the tension applied thereby across the wound closure is uniform with each staple application. As a result, scarring may be minimized. In contrast, each suture is generally secured to a separate needle, requiring a great amount of manual work to grasp each needle, form the stitch, tie off the suture, and trim the excess suture thread. Also, the tension of each suture may vary significantly, causing puckering and uneven scar formation.
However, the techniques of surgical stapling have not gained immediate acceptance, due primarily to the shortcomings of the prior art surgical stapling tools. One significant drawback in general is that the tools now available do not provide clear visualization of the intended placement of the staples, due to the configuration and bulk of the tools themselves. Thus the surgeon must approximate the placement of each staple, and this uncertainty is unacceptable.
Also, those prior art tools which store a large number of staples do so by arranging the staples in parallel, stacked column fashion, with the column generally extending toward the dispensing end of the tool. Generally one of these staples is separated from the column and crimped about an anvil member to drive the staple legs into opposed sides of the wound to be closed. However, the staple cannot travel far from the column before being crimped without requiring a mechanism which is unwieldy and visually obstructive. That is, the legs of the staple cannot be extended far enough to be seen clearly before the crimping step begins. As a result, the visualization problem noted above is exacerbated.
Some of the surgical stapling tools developed in the prior art have attempted to overcome this problem by storing the staples in single file, points-first orientation, either in a feed channel or secured to an endless belt which advances about rollers. In either case, the utilization of storage space is poor, and few staples can be stored in one tool. As a result either the tool must be resupplied frequently, diluting the advantage of speed in application, or several disposable tools must be used, creating an unwarranted expense. Thus this approach has also proved to be unacceptable as a common medical practice.
Any surgical stapling tool must be configured to be grasped and operated easily, and this factor has led to the use of either pistol-like designs or ring-handle, scissor- or plier-type tools. With either design approach it is difficult to rotate the tool about the longitudinal axis to apply staples at any angle about the nominal line of sight of the surgeon. Some tools are provided with dispensing head ends which rotate about the longitudinal axis, but the rotational freedom is generally limied. In some tools commercially available, the dispensing head rotates eccentrically about the axis, requiring that the surgeon continually adjust to the changing offset between the barrel axis and the delivery point of the tool. This factor has also served to discourage the use of surgical staples in place of sutures.